hi every one, i'm writing a code to split a file into many files with a size specified in the code, and then it will join these parts again.
the problem is with the joining code,it doesn't work and i can't figure what is wrong, can any one help?
this is my code.
import java.io.*;
import java.util.*;
public class StupidSplit {
static final int Chunk_Size = 10;
static int size =0;
public static void main(String[] args) throws IOException {
String file = "b.txt";
int chunks = DivideFile(file);
System.out.print((new File(file)).delete());
System.out.print(JoinFile(file, chunks));
}
static boolean JoinFile(String fname, int nChunks) {
/*
* Joins the chunks together. Chunks have been divided using DivideFile
* function so the last part of filename will ".partxxxx" Checks if all
* parts are together by matching number of chunks found against
* "nChunks", then joins the file otherwise throws an error.
*/
boolean successful = false;
File currentDirectory = new File(System.getProperty("user.dir")); // get current directory
File[] fileList = currentDirectory.listFiles();
/* populate only the files having extension like "partxxxx" */
List<File> lst = new ArrayList<File>();
//
Arrays.sort(fileList);
for (File file : fileList) {
if (file.isFile()) {
String fnm = file.getName();
int lastDot = fnm.lastIndexOf('.');
// add to list which match the name given by "fname" and have
//"partxxxx" as extension"
if (fnm.substring(0, lastDot).equalsIgnoreCase(fname)
&& (fnm.substring(lastDot + 1)).substring(0, 4).equals("part")) {
lst.add(file);
}
}
}
/*
* sort the list - it will be sorted by extension only because we have
* ensured that list only contains those files that have "fname" and
* "part"
*/
File[] files = (File[]) lst.toArray(new File[0]);
Arrays.sort(files);
System.out.println("size ="+files.length);
System.out.println("hello");
/* Ensure that number of chunks match the length of array */
if (files.length == nChunks-1) {
File ofile = new File(fname);
FileOutputStream fos;
FileInputStream fis;
byte[] fileBytes;
int bytesRead = 0;
try {
fos = new FileOutputStream(ofile,true);
for (File file : files) {
fis = new FileInputStream(file);
fileBytes = new byte[(int) file.length()];
bytesRead = fis.read(fileBytes, 0, (int) file.length());
assert(bytesRead == fileBytes.length);
assert(bytesRead == (int) file.length());
fos.write(fileBytes);
fos.flush();
fileBytes = null;
fis.close();
fis = null;
}
fos.close();
fos = null;
} catch (FileNotFoundException fnfe) {
System.out.println("Could not find file");
successful = false;
return successful;
} catch (IOException ioe) {
System.out.println("Cannot write to disk");
successful = false;
return successful;
}
/* ensure size of file matches the size given by server */
successful = (ofile.length() == StupidSplit.size) ? true : false;
}
else {
successful = false;
}
return successful;
}
static int DivideFile(String fname) {
File ifile = new File(fname);
FileInputStream fis;
String newName;
FileOutputStream chunk;
//int fileSize = (int) ifile.length();
double fileSize = (double) ifile.length();
//int nChunks = 0, read = 0, readLength = Chunk_Size;
int nChunks = 0, read = 0, readLength = Chunk_Size;
byte[] byteChunk;
try {
fis = new FileInputStream(ifile);
StupidSplit.size = (int)ifile.length();
while (fileSize > 0) {
if (fileSize <= Chunk_Size) {
readLength = (int) fileSize;
}
byteChunk = new byte[readLength];
read = fis.read(byteChunk, 0, readLength);
fileSize -= read;
assert(read==byteChunk.length);
nChunks++;
//newName = fname + ".part" + Integer.toString(nChunks - 1);
newName = String.format("%s.part%09d", fname, nChunks - 1);
chunk = new FileOutputStream(new File(newName));
chunk.write(byteChunk);
chunk.flush();
chunk.close();
byteChunk = null;
chunk = null;
}
fis.close();
System.out.println(nChunks);
// fis = null;
} catch (FileNotFoundException fnfe) {
System.out.println("Could not find the given file");
System.exit(-1);
} catch (IOException ioe) {
System.out
.println("Error while creating file chunks. Exiting program");
System.exit(-1);
}System.out.println(nChunks);
return nChunks;
}
}
}
